Calculate the wavelength in nanometers, of the spectral line produced when an electron in a hydrogen undergoes the transition from the energy level n = 5 to the level n = 1.

Arectangle has a diagonal 20 inches long that forms angles of 60 and 30 with the sides. find the perimeter of the rectangle. for geometry

Me as soon as possible! me as soon as possible!

Water is a highly important natural resource. which of these would be the best method to conserve water? a) drinking bottled water b) monitoring the ph of rivers c) treating and re-using wastewater d) testing nitrate levels in groundwater